15w40 vs 5w40 ? - Diesel Bombers
Diesel Bombers
Go Back   Diesel Bombers > Dodge Cummins > Dodge Truck and Cummins Turbo Diesel Forum
Search


Dodge Truck and Cummins Turbo Diesel Forum Discussion of General Topics related to All Cummins Engines or Dodge Trucks

What's the difference really? Do we need it to be thinner and flow better on startup or thicker? The chart in manual has both but only 5w40 covering the whole range of temps?... JOIN NOW TO REMOVE TRACER

15w40 vs 5w40 ?

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 02-25-2011, 07:53 PM
Diesel Enthusiast

   
Default 15w40 vs 5w40 ?

What's the difference really? Do we need it to be thinner and flow better on startup or thicker? The chart in manual has both but only 5w40 covering the whole range of temps?
Reply With Quote
  #2  
Old 02-26-2011, 12:22 AM
kazairl's Avatar
Diesel Bomber

   

Default

15w-40 is thicker and is slightly better for higher temps.

Real world application? Run whichever you want. The difference isn't that great. Most people run 15w-40 because it is more readily available.

kazairl's Sig:
My Sig of excessive size
Reply With Quote
  #3  
Old 02-26-2011, 12:23 AM
Diesel Enthusiast

   
Default

Alright. Thanks for your help.
Reply With Quote
  #4  
Old 02-26-2011, 12:40 AM
Diesel Enthusiast

   

Default

i think the diesel oil has more adatives. harley davidson says in service manual to run harley oil or diesel oil no auto oil.
Reply With Quote
  #5  
Old 02-26-2011, 01:53 AM
Diesel Enthusiast
Lookin for 12's with my 37's

   
Send a message via AIM to madmikeismad Send a message via MSN to madmikeismad Send a message via Skype™ to madmikeismad

Default

Just make sure it's diesel approved. 5w will flow a little better on cold starts. But I run 15w and it hits -30F here, I've never had any problems with pressure.

A thread was just started about this over on CF too. Turned into a fight .

madmikeismad's Sig:98 12v ccsb - GAUGES, Frankentrans, Custom 4in straight, 5x.014's, no plate, 2095 plug, 4k w/springs, 15.5*, BHAF, TC lockup switch in the armrest, 6.5in rear/7in front, Custom humvee tires/wheels w/ beadlocks, DT Track Bar, Shackle Flip, 37's, Bedlined Rockers/Bumpers, Tinted Tails, Black Heads w/ HID's, Smoked Cab Lights http://picasaweb.google.com/mch8223/Diesel#
Reply With Quote
  #6  
Old 02-26-2011, 05:49 AM
Diesel Enthusiast

   

Default

Heavier weight in the summer, lower weight in the winter.

The reason is obvious; tempurature. Sure, 5W40 will handle the high temps but I'd rather have a bit more protection.

MarineOne's Sig:2008 Dodge Ram 3500 QCLB SRW 6.7L - Titan 50 gallon fuel tank, Aero Muffler 4040XL, Firestone Air Springs, Nathan AirChime K3LA

2006 Dodge Ram 2500 QCSB 5.9L - Wife's truck - totally stock
Reply With Quote
  #7  
Old 02-26-2011, 09:41 AM
Authorized Amsoil Dealer
on the Harley if not here

   

Default

Both run the same at operating temps as a 40 weight. Startup is where most engine wear can occur so using a 5W in cold temps should theoretically help with this. As mentioned, a 15W can work to pretty low temps.
You're correct in that 5W are easier to find these days. Many companies have gone away from the 15 as 5 will serve all purposes and saves them from having to make several grades.
Being in Georgia, a 15 will easily serve you purpose.
Reply With Quote
  #8  
Old 02-26-2011, 07:53 PM
kazairl's Avatar
Diesel Bomber

   

Default

Originally Posted by pukie370 View Post
i think the diesel oil has more adatives. harley davidson says in service manual to run harley oil or diesel oil no auto oil.
Diesel oil has higher anti wear properties than gasoline oil. It handles high temps pretty good to. However, the biggest reason to NOT use gasoline oil is because of the friction modifiers it has in it. They were designed to improve fuel economy by creating less drag.Good for cars bad for wet clutch systems. The engines and transmissions in most motorcycles share the same oil.

I'm not much of a Harley guy, so I wouldn't know which ones share oil and which ones wouldn't.
You're correct in that 5W are easier to find these days. Many companies have gone away from the 15 as 5 will serve all purposes and saves them from having to make several grades.
Not around here. 15w-40 is by far the most prolific.

Last edited by kazairl; 02-26-2011 at 07:55 PM.
Reply With Quote
  #9  
Old 02-27-2011, 06:53 AM
Diesel Enthusiast
Lookin for 12's with my 37's

   
Send a message via AIM to madmikeismad Send a message via MSN to madmikeismad Send a message via Skype™ to madmikeismad

Default

Yeah, I've personally never seen 5w-40
Reply With Quote
  #10  
Old 02-27-2011, 08:53 AM
Diesel Enthusiast
wanted 2500 hd chevy with 6.0l gasser cheap need it for parts

   

Default

walmart has it in rotella t in a blue bottle

92typhoon937's Sig:1997 cummins 5 spd dually new hauler
1983 chevy 1 ton rollback jerry dan aluminum bed 6.2L diesel
1992 gmc typhoon 36000 orignal miles second owner
1993 gmc typhoon 6.0L and 4l80e acquired now to build it
1991 chevy s-10 daily driver
Reply With Quote
 
 
 
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search


 
All times are GMT -5. The time now is 04:53 AM.

Copyright And Legal Notice Links Of Interest

Diesel Bombers ® - All Content Protected Under Intellectual Property Rights Law of Registered Trademarks
Reg. No. 3,494,401 Cls. 100, 101 & 104 Under Int. Cl. 38
USE AT YOUR OWN RISK WE HOLD NO LIABILITY FOR ANY CONTENT RIGHT, WRONG OR INDIFFERENT

Protected by Copyscape Duplicate Content Check


Diesel Bombers Dodge Cummins Forum Section Diesel Bombers Ford Powerstroke Forum Section Diesel Bombers Chevy GMC Duramax Forum Section